Last updated: Thursday, 23, December, 2010
Key InformationAppropriate Tests


Term used to indicate an increased risk of thrombosis. See blood abnormalities under Thrombosis, arterial and venous.

Specific factor assays.

Factor V Leiden mutation

Prothrombin gene mutation (G20210A)

Protein C, Protein S deficiency

Antithrombin deficiency

Activated protein C resistance

Elevated F VIII:C

Acquired causes

Underlying malignancy

May be occult. Particularly adenocarcinomas

Pregnancy and exogenous oestrogens

Immobility, postoperative state, venous stasis

Cardiolipin antibodies

May be part of the antiphospholipid antibody syndrome

Elevated homocysteine

This may be due to an underlying genetic lesion or reflect deficiency in folate, B12 and/or pyridoxine in the diet. Testing for the methyl tetra hydrofolate reductase mutation may be indicated.

Lupus inhibitor

Myeloproliferative disorders

Paroxysmal nocturnal haemoglobinuria